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The choice of the optimal benzodiazepine to treat prehospital status epilepticus is unclear. Lorazepam is preferred in the emergency department, but concerns about nonrefrigerated storage limits emergency medical services (EMS) use. Midazolam is increasingly popular, but its heat stability is undocumented.This study evaluated temperature-dependent degradation of lorazepam and midazolam after 60 days in the EMS environment.Lorazepam or midazolam samples were collected prior to (n = 139) or after (n = 229) 60 days of EMS deployment during spring-summer months in 14 metropolitan areas across the United States. Medications were stored in study boxes that logged temperature every minute and were stored in EMS units per local agency policy. Mean kinetic temperature (MKT) exposure was derived for each sample. Drug concentrations were determined in a central laboratory by high-performance liquid chromatography. Concentration as a function of MKT was analyzed by linear regression.Prior to deployment, measured concentrations of both benzodiazepines were 1.0 relative to labeled concentration. After 60 days, midazolam showed no degradation (mean relative concentration 1.00, 95% confidence interval [CI] 1.00-1.00) and was stable across temperature exposures (adjusted R(2) -0.008). Lorazepam experienced little degradation (mean relative concentration 0.99, 95% CI 0.98-0.99), but degradation was correlated to increasing MKT (adjusted R(2) 0.278). The difference between the temperature dependence of degradation of midazolam and lorazepam was statistically significant (T = -5.172, p0.001).Lorazepam experiences small but statistically significant temperature-dependent degradation after 60 days in the EMS environment. Additional study is needed to evaluate whether clinically significant deterioration occurs after 60 days. Midazolam shows no degradation over this duration, even in high-heat conditions.

BACKGROUND/STUDY CONTEXT: Musculoskeletal pain after motor vehicle collision is a substantial public health problem. The number of elderly individuals experiencing motor vehicle collision is increasing. The authors conducted analyses of data collected as part of a prospective observational study of outcomes after motor vehicle collision to estimates rates of persistent pain, pain interference, and change in physical function in patients 65 or older.Adults presenting to one of four emergency departments following motor vehicle collision without severe or life-threatening injury were recruited. Outcomes were assessed using 1-month follow-up surveys.The frequencies of persistent moderate or severe pain resulting from the motor vehicle collision were similar among elderly and nonelderly participants, both in the neck region (27% vs. 30%) and in any region (60% vs. 56%). For both elderly and nonelderly patients, persistent pain was associated with high levels of interference with physical activity and mood.Further studies of this vulnerable and rapidly increasing injury population are needed.